Apparatus for making extruded nets having integral stand junctions

ABSTRACT

An apparatus for making an extruded net-like structure having intersecting mesh strands in which at least portions of certain mesh strands pass directly through other mesh strands at their locations of intersection and are bonded thereat.

United States Patent Fairbanks [45 Apr, 4, 1972 [541 APPARATUS FORMAKING EXTRUDED 3,34,071 2/1966 Ward et al. ..l56/l67 x 3, 38,545 111970 Smith ..18/12N NETS HAVING INTEGRAL STAND 3,227,184 1/1966 Andersonet all. ..156/167 X JUNCTIONS 3,123,512 3/1964 Mercer ..l56/167 xInventor: Theodore H. b k Li p Pa. Dutton et a1 X [73] Assignee: FMCCorporation, Philadelphia, Pa. Primary Examiner-Benjamin A. BorcheltAssistant ExaminerG. E. Montone [22] Ffled: 1969 Attorney-Thomas R.OMalley, George F. Mueller and Eu- 21 Appl. No.: 872,089 gene HOYSIY[57] ABSTRACT [52] US. Cl. ..l56/441, 18/12 N, 156/167 An apparatus formaking an extruded neblike Structure having D0 [51] Int. Cl. 411 3/16intersecting mesh strands in which at has portions of certain [58] FieldOf ear h 13/12 N mesh strands pass directly through other mesh strandsat their locations of intersection and are bonded thereat. [56]References Cited 5 Claims, 8 Drawing Figures Patented April 4, 19723,654,031

2 Sheets-Sheet l Patented April 4, 1972 3,654,031

2 Sheets-Sheet 2 APPARATUS FOR MAKING EXTRUDED NETS HAVING INTEGRALSTAND JUNCTIONS The present invention relates to an apparatus for makingimproved net-like structures or fabrics US. Pat. No. 2,919,467 isdirected to the manufacture of net-like structures in which meshintersecting portions are each composed of an integrally extrudedplastic mass and mesh strand-forming portions are formed as divisions ofsuch intersection-forming portions, with the whole fabric or structurebeing an integral entity. The process and apparatus described in thispatent does facilitate continuous production of satisfactory net-likestructures but at a very slow rate and, therefore, involves highoperating costs.

While other known processes and apparatus may provide for moreeconomical production of net-like structures, the structures producedare, in general, lacking in desired physical properties. For example,one of the fastest processes for making net-like structures is toextrude a series of diagonally crossing strands which are subsequentlybonded at their crossing points under heat and pressure. In suchstructures, however, the bonded strand intersections lack desiredstrength and are generally weaker than the unitary intersections presentin net-like structures formed by the process described in theabove-noted patent. Accordingly, a primary object of this invention isto provide a generally new or improved and more satisfactory apparatusfor making a net-like structure or fabric.

Another object is the provision of an apparatus for making a net-likestructure having strands and integral strand junctions at which at leastportions of one strand passes through another strand.

Still another object is to provide an improved extrusion apparatus formaking net-like structures having strands and integral strandintersections or junctions. V

A further object is the provision of an improved and apparatus formaking multi-layer net-like structures by extrusion in which at leastportions of certain strands pass through other strands and are bondedthereat to form integraljunctions.

These and other objects are accomplished in accordance with the presentinvention by an apparatus from which streams of flowable strand-formingmaterial are continuously extruded at spaced intervals along each of atleast three parallel lines, which are either straight or circular, withthe streams along alternate of such lines being aligned and brought intocontact with each other at a location below their points of extrusion.Relative movement is provided between the streams in adjacent lines, attheir points of extrusion, with the streams in the alternate of suchlines maintaining their aligned relationship. The alternate streamswhich are moved are moved in unison; that is, in the same direction andat the same rate of speed, along their respective parallel lines so asto maintain their aligned relationship throughout. Concomitantly withsuch movement, all of the extruded streams are continuously advanced ina direction away from their points of extrusion.

The streams which are moved along their respective lines of extrusion asdescribed above assume paths which are inclined relative to the paths ofstreams which are extruded along adjacent lines. The aligned streamswhich are extruded along alternate lines will contact with each other,except at locations at which such streams intersect and contact withstreams which are extruded along lines between such alternate lines.Thereafter, all of the streams of strand-forming material are set intostrands to provide integral net-like structures.

Relative movement between streams extruded along adjacent lines may beachieved by moving the streams along one or both of such lines. If thestreams along both of such lines are moved, the streams along one linemay be moved in the same direction but at a different speed than thestreams which are extruded along an adjacent line or in a directionopposite to the streams in such adjacent lines.

If in the operation of the apparatus of the present invention streamsare extruded at spaced intervals along each of only three lines thestreams which are extruded along the alternate lines and which arealigned with each other will contact, ex-

cept at locations at which such streams intersect with streams which areextruded along the middle of such three lines. Each pair of aligned andcontacting streams, when set, will appear as a composite, unitary strandin the finished net-like structure. The streams which were originallyextruded along the middle of the three lines will appear as individualstrands which pass through and are bonded to such composite strands.

As a further example of the operation of the apparatus of the presentinvention, streams may be extruded at spaced intervals along each ofonly four lines. in this instance there will be, of course, two pairs ofalternate lines and the aligned streams in each such pair will contactwith each other, except at the locations at which such streams intersectwith the streams which are extruded along adjacent of such lines. Eachpair of aligned and contacting streams, when set, will appear as acomposite unitary strand, with one half of each of such strands passingthrough and being bonded to each composite strand with which it crosses.

More specifically, the apparatus for carrying out the method of thepresent invention includes means having orifices for extruding aplurality of streams of flowable strandforming material at spacedintervals along each of at least three lines, which may be straight orcircular. The orifices in these means are oriented so that the streamsextruded along each such line are aligned with streams in alternatelines. Means are included for providing relative movement betweenorifices located along adjacent of such lines, with the orifices alongalternate lines moving in unison. Included also are means for advancingall of the extruded streams in a direction away from the extrusion meansand for setting of such streams.

More specifically, the extruding means may include a single extrusionchamber having a bottom wall defined by at least three elongated diemembers which are disposed in side-byside relationship. Each of suchmembers is formed with orifices, with the orifices in alternate diemembers being aligned with each other. Such apparatus would includemeans for providing relative movement between the adjacent die members.

An alternative, and preferred arrangement which is hereafter describedin detail, includes at least three die members of annular or conicalconfiguration, each of which has a chamber defined by a circular endwall having orifices therein and a pair of spaced side walls. These diemembers are nested or stacked in spaced-apart relationship along acommon axis, with the end walls thereof located adjacent to each other.The orifices in alternate of such die members are maintained radiallyaligned with each other and at least certain of the die members arerotated about the common axis to provide for relative movement betweenadjacent of such members.

Streams of flowable strand-forming material extruded from orifices inalternate of the die members are brought into or are encouraged tocontact with each other along their lengths by suitable deflectingmeans, such as rings or mandrels over or through which travel theextruded streams, or by having the axes of such aligned orificesinclined to direct the streams issuing therefrom along converging paths.Using this latter arrangement with elongated die members, the axes ofthe orifices in alternate of such members would lie in planes whichintersect with each other at an acute angle. In an apparatus employingdie members of annular or conical configuration, parallel lines drawnthrough the axis of orifices in different die members will be in planeswhich intersect each other at an acute angle.

The orifices in the individual die-carrying members preferably are butneed not be of like size and/or shape and may difier from those in theother die-carrying members with which they are aligned. Moreover, thefiowable strandforming material delivered to the individual die-carryingmembers may differ in composition and/or pigmentation to impartdifferent properties as for example, color or texture to theintersecting strands of the resulting net-like structures. While streamsmust be extruded along at least three lines, the maximum number of suchparallel lines along which streams may be extruded will be limited bythe particular construction of apparatus employed and the ability toproperly set the extruded streams.

The teachings of the present invention are applicable for use with avariety of materials, which are referred to by the term "plastic,"including materials which are thermoplastic, such as polyamides orsuperpolyamides, polyesters, polyvinyl chloride, copolymers thereof,polyolefins, cellulose acetates, etc., natural or synthetic rubbers,thermosetting materials or wet-spinnable materials, such as viscose,cupro-ammonium cellulosic, or carboxymethyl cellulose. Such materialsmay include various additives such as stabilizers, dyes, foaming agents,etc., if so desired. It will be apparent that the manner by which theextruded junction and mesh-strand forming streams are set will dependupon the particular material which is being employed.

For a greater understanding of the invention, reference is made to thefollowing detailed description and drawing in which FIG. 1 is adiagrammatic side view of the apparatus of the present invention, with aportion thereof being broken away;

FIG. 2 is a vertical section, on an enlarged scale, of a portion of theapparatus shown in FIG. 1;

FIG. 3 is a bottom view ofa portion of the apparatus shown in FIGS. land2;

FIG. 4 is a horizontal section taken along the lines IV-IV of FIG 2;

FIG. 5 is a horizontal section taken along the lines VV of FIG. 2;

FIG. 6 is a fragmentary view of one form of net-like structure formedwith the apparatus of the present invention;

FIG. 7 is a view similar to FIG. 6 of another form of net-likestructure; and

FIG. 8 is a fragmentary view ofa portion ofa modified form of apparatus.

With reference to FIGS. 1 and 2 of the drawing, the preferred apparatusthere illustrated includes a plurality of die-carrying members 21, 23,and 27 disposed in nested or stacked relationship relative to a commonaxis, indicated at 29, and having chambers 31, 33, and 37, respectivelyinto which flowable strand-forming material is delivered. As shown on anenlarged scale in FIG. 2, each of the die-carrying members 21, 23, 25and 27 includes a pair of radially spaced annular side walls 39 and 41,a pair of vertically spaced top walls 43 and 45 and a circular end wall47 extending between and across the respective pairs of side walls 39and 41. Desirably, the walls 43 and 45 of the respective die-carryingmembers are connected to each other as by screws 49.

Orifices 51 extend through the end walls 47 and open along the exposedsurfaces thereof. In the apparatus shown in FIG. 2, the exposed surfacesof the individual end walls 47 are disposed along a common horizontalplane while the longitudinal axes of the orifices extend through suchsurfaces are inclined so that streams of flowable strand-formingmaterial issuing from such orifices are directed along converging paths.

The die-carrying members 21, 23, 25 and 27 are supported from a fixedframe 53 by a housing 55 which is formed ofa series of like segments 57.More particularly, the frame 53 includes a depending sleeve 59 which isinternally threaded at 61 for connection with one of the series ofsegments 57. These segments resemble in appearance a pulley having a hub63 and a pair of annular flanges 65. Each hub 63 has an internaldiameter which corresponds with that of the sleeve 59 and, as shown inFIGS. 4 and 5, is formed with a series of annularly spaced, radialpassages 67 which open inbetween the flanges 65. The segments 57 areprovided with external threads 69 at one end thereof and internalthreads 71 at their opposite ends to facilitate connection of thesegments 57 to each other and to the sleeve 59. Circular ribs 73 projectfrom the outer surfaces of the flanges 65 of each of the segments 57 andare adapted to seat snugly, yet slidably, within mating recesses 75formed along the opposing surfaces of the walls 43 and 45 of therespective die-carrying members.

The die-carrying members 21, 23, 25 and 27 may be connected onto therespective housing segments 57 after such segments have been threadedinto each other and the sleeve 59 or, alternatively and preferably, thedie-carrying members may be attached to the respective segments 57afterwhich the segments are threaded together and to the sleeve 59.While the apparatus of the present invention must include at least threedie-carrying members, additional die-carrying members may be employed,depending upon such factors as the characteristics desired in thefinished net-like structure and the ability to incorporate suchadditional die-carrying members into the apparatus in stacked or nestedrelationship.

As shown in FIG. 2, a plug 77 is threaded into the lowermost of theseries of segments 57 to close off the lower end of the housing, andtogether with a spacer 79, assist in maintaining the innermost of thenested die-carrying members in desired position. During assembly, thedie-carrying members are oriented so that the orifices 51 in alternateof such members are aligned radially with each other, as shown in FIG.3.

In the embodiment illustrated in FIGS. 1-5 of the drawing, all of thedie members 21, 23, 25 and 27 are simultaneously rotated about thecommon axis 29, with alternate of such members moving in unison and in adirection opposite to the die-carrying members adjacent thereto. Suchmovement is effected by a drive shaft 81, which is turned by suitablemeans, not shown, and extends through an opening 83 in the frame 53, thesleeve 59 and the housing 55 and terminates adjacent to the plug 77. Theshaft 81 has an outside diameter which is substantially less than theinside diameters of the sleeve 59 and housing segments 57, for reasonsas hereafter described, and is provided along its periphery withlongitudinally extending teeth 85.

A pinion gear 87, rotatably carried by a shaft 89, is positionedpositioned within at least one of the radial passages 67 of each of thehousing segments 57 and meshes with the teeth 85 on the drive shaft 81.Rotation of the gears 87 is transmitted to ring gears 91, which areattached within the respective die-carrying members by screws 93. In thecase of the diecarrying members 21 and 25 the gears 87 mesh directlywith the ring gears 91 which are aligned therewith and thus both of suchmembers 21 and 25 are together in the same direction. The ring gears 91fixed to the die-carrying members 23 and 27, on the other hand, aredriven by the gears 87 with which they are aligned through idler gears95. With this arrangement the members 23 and 27 are together driven in adirection opposite to that of the members 21 and 25. As shown in FIGS. 2and 5, the idler gears 95 are rotatably carried by shafts 97 which aredisposed within the radial passages 67 of the housing segments 57 andextend between the flanges thereof.

As heretofore mentioned, the periphery of the drive shaft 81 is spacedfrom the inside walls of the sleeve 59 and housing segments 57 to thusprovide an annular chamber 99. From a suitable source, not shown,flowable strand-forming material is continuously delivered underpressure into the chamber 99 through a conduit 101 which passes throughan opening 103 in the sleeve 59. Flowing through the radial passages 67in the housing segments 57, the strand-forming material enters into andfills the respective die-carrying members 21, 23, 25 and 27 and issuesfrom the orifices 51 thereof as streams. A seal 105 may be provided atthe lower end of the chamber 99 and openings 107 may be formed in thering gears 91 to minimize areas at which strand-forming material collectand remain stagnant.

The streams of strand-forming material issuing from radially alignedorifices 51 will contact with each other along their lengths to provide,when set, a composite strand as shown at 109 and 111 in FIG. 6. Sincethe die-carrying members 21 and 25 are rotated in a direction oppositeto the die-carrying members 23 and 27 during such extrusion adjacentstreams will intersect with each other to provide, when set, a junctionas shown at 113 in FIG. 6. Setting of the extruded streams of flowablestrand-forming material may be achieved by any convenient means, as byair cooling in the case of molten strandforming material, and iseffected only after the streams have made their desired contact.

Conventional take-up means, not shown, are employed for collecting thefinished net'like structure and serve to advance all of the extrudedstreams away from their respective orifices. If desired, a ring 1 may bepositioned to engage with at least some of the extruded streams aftertheir surfaces have been set to encourage or provide for the desiredcontact between the streams. In lieu of the ring 115, a ring or mandrelmay be located within the circles of extruded streams to perform a likefunction,

In the finished net-like structures shown in FIG. 6 the compositestrands 109 and 11 are interlocked and bonded to each other at thejunctions 113, at which one half of each composite strand passes throughthe other thereof. In the event the apparatus described is employed withonly three die-carrying members, a structure as shown in FIG. 7 will beprovided in which strands 117, formed of unitary extruded streams passthrough and are bonded to composite strands 119 at each lo cation ofintersection thereof.

If desired, die-carrying members may be of conical configuration, asshown at 121, 123, 125 and 127 in FIG. 8. Such diecarrying members wouldbe nested together as illustrated and would be operated in substantiallythe same manner as the diecarrying members 21, 23, and 27 shown in FIGS.1-5.

IClaim:

1. Apparatus for continuously extruding a net-like structure includingdie-carrying members having orifices for extruding a plurality ofstreams of flowable strand-forming material at spaced intervals alongeach of at least three lines with the individual orifices in alternateof said die-carrying members each being aligned with a separate orificein a die-carrying member which is located in alternating relationshiptherewith, the axes of the orifices which are aligned with each otherbeing disposed along converging paths to cause streams of flowablestrand-forming material issuing therefrom to merge and together form aunitary stream, means for relatively moving adjacent die-carryingmembers while maintaining substantially constant the aligned and axialrelationships of the oriflees in the alternate of said die-carryingmembers to intermittently interrupt the mergence of streams issuing fromaligned orifices in alternate of said die-carrying members by streamsissuing from orifices of a die-carrying member located between suchalternate die-carrying members, means for advancing all of the extrudedstreams in a direction away from the extruding means, and means forsetting the extruded streams to provide an integral net-like structure2. Apparatus as defined in claim 1 wherein said die members each includea chamber defined by a circular end wall having an exposed surface and apair of spaced side walls, said die members being disposed in nestedrelationship along a common central axis with the circular walls thereoflocated in generally adjacent relationship to each other, said orificesextending through said circular end walls and opening along the exposedsurfaces thereof, and means for delivering flowable strand-formingmaterial under pressure into each of said chambers.

3. Apparatus as defined in claim 1 wherein said means for relativelymoving adjacent die-carrying members includes means for moving all ofsaid members with the alternate of said members moving in unison and ina direction opposite to the die members directly adjacent thereto.

4. Apparatus as defined in claim 1 wherein said means for relativelymoving adjacent die-carrying members includes means for moving all ofsaid members in the same direction with alternate die-carrying membersbeing moved in unison and at a rate of speed which differs from that ofa die-carrying member therebetween.

5. Apparatus as defined in claim 2 further including means for urgingthe streams in the alternate circles into contact with each other andthe streams in the circles therebetween, said means including a ringfixed in spaced relationship with the die-carrying members and havingits center located along the common axis, said ring having an internalradius which is smaller than the die-carrying member oflargest radius.

Patent N0, D t d April 4,

Inventor s) Theodore H Fairbanks It is certified that error appears inthe above-identified patent and that said Letters Patent are herebycorrected as shown below:

In the title, both instances, "STAND" should read --STRAND--. Col. 1,line 23, after "process" insert --and apparatus-; line 35, after"improved" delete "and". Col. 4, line 34, delete "positioned". Col. 5,line 11, "11" should read --lll'---.

Signed and sealed this 22nd day of August 1972.

(SEAL) Attest:

EDWARD M.FLETCHER, JR. ROBERT GOTTSCHALK Attesting, Officer-Commissioner of Patents FORM P040550 (069) uscoMM-Dc scam-ps9 ,5.GOVERNMENT PRINTING OFFICE t 1959 0-365334

1. Apparatus for continuously extruding a net-like structure includingdie-carrying members having orifices for extruding a plurality ofstreams of flowable strand-forming material at spaced intervals alongeach of at least three lines with the individual orifices in alternateof said die-carrying members each being aligned with a separate orificein a die-carrying member which is located in alternating relationshiptherewith, the axes of the orifices which are aligned with each otherbeing disposed along converging paths to cause streams of flowablestrand-forming material issuing therefrom to merge and together form aunitary stream, means for relatively moving adjacent diecarrying memberswhile maintaining substantially constant the aligned and axialrelationships of the orifices in the alternate of said die-carryingmembers to intermittently interrupt the mergence of streams issuing fromaligned orifices in alternate of said die-carrying members by streamsissuing from orifices of a die-carrying member located between suchalternate die-carrying members, means for advancing all of the extrudedstreams in a direction away from the extruding means, and means forsetting the extruded streams to provide an integral net-like structure.2. Apparatus as defined in claim 1 wherein said die members each includea chamber defined by a circular end wall having an exposed surface and apair of spaced side walls, said die members being disposed in nestedrelationship along a common central axis with the circular walls thereoflocated in generally adjacent relationship to each other, said orificesextending through said circular end walls and opening along the exposedsurfaces thereof, and means for delivering flowable strand-formingmaterial under pressure into each of said chambers.
 3. Apparatus asdefined in claim 1 wherein said means for relatively moving adjacentdie-carrying members includes means for moving all of said members withthe alternate of said members moving in unison and in a directionopposite to the die members directly adjacent thereto.
 4. Apparatus asdefined in claim 1 wherein said means for relatively moving adjacentdie-carrying members includes means for moving all of said members inthe same direction with alternate die-carrying members being moved inunison and at a rate of speed which differs from that of a die-carryingmember therebetween.
 5. Apparatus as defined in claim 2 furtherincluding means for urging the streams in the alternate circles intocontact with each other and the streams in the circles therebetween,said means including a ring fixed in spaced relationship with thedie-carrying members and having its center located along the commonaxis, said ring having an internal radius which is smaller than thedie-carrying member of largest radius.